Method and means for treating wells



June 1, 1965 c. M. scHwAB METHOD AND MEANS FOR TREATING WELLS 3 Sheets-Sheet 1 Filed Aug. 5. 1957 INVENTOR Carl M. Schwab Fig.|

June 1, 1965 c; M. SCHWAB METHOD AND MEANS FOR TREATING WELLS 3 Sheets-Sheet 2 Filed Aug. 5, 1957 6 INVENTOR Carl M. Schwab BY flf/ Fig.4

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ATTORNEY June 1, 1965 c. M. SCHWAB METHOD AND MEANS FOR TREATING WELLS 3 Sheets-Sheet 3 Filed Aug. 5, 1957 Fig 40 Z 4 5 mqiflfi fim B P. W 2 6 9655 .I z v p n er z x i8 /44 mm. m w i D a w m M INVENTOR M. Schwob Carl Fig.8

ATTORNEY United States Patent 3,186,483 METHOD AND MEANS FOR TREATING WELLS Carl M. Schwab, Pasadena, Tex., assignor, by mesne assignments, to Otis Engineering Corporation, Dallas County, Tex., a corporation of Delaware Filed Aug. 5, 1957, Ser. No. 676,299 23 Claims. (Cl. 166-42) This invention relates to new and useful improvements in methods and means for treating and completing oil wells and, more particularly, to methods and means for introducing treating fluids into earth formations through which the well extends.

In the completion and in certain treating processes of an oil well it is genenally desirable to be able to place a treating fluid at a predetermined position in a well casing and to then apply pressure from the surface to said fluid to force the fluid outwardly into the earth formations or strata surrounding the well casing. It may be desirable to force the fluid outwardly at such predetermined position either through the lower end of the casing string or through perforations previously made in the wall of the casing.

In the past, the desired treating fluid was pumped to the predetermined position in the well by installing a pipe or tube within the well casing and by applying pressure by means of a pump at the surface and pumping said fluid downwardly into said pipe. In this process any existing liquid in the casing of the well would be displaced by the entering treating fluid and flow upwardly in the casing around the inserted pipe. If the casing was initially filled with liquid, the liquid would be displaced upwardly from the well. When the treating fluid had been so pumped into position or spotted in place, the exit for the returning fluid was closed, either at the surface by means of a valve, or within the well by means of a packer or other similar device. Pressure was then applied to the treating fluid through the inserted pipe by means of the pump at the surface, and the fluid was forced outwardly from or through the well casing to treat or complete the well. Obviously, the surface pumps and connecting hoses necessary to generate and apply high pressures to a well pipe are expensive and cumbersome as well as not always being available. In addition, if the complete length of the well casing is subjected to the high pressures required, there is serious risk of rupture of the casing.

One object of the invention is to provide a new and improved conduit means for introducing treating fluid into a well casing at a predetermined location in the well.

Another object is to provide a conduit means, of the type described, having a by-pass means provided with an expansible sealing means for sealing between the conduit and the well easing whereby, when the sealing means is expanded, fluid flow between the by-pass means and the well casing is prevented.

A further object is to provide a conduit means, of the type described, having a closure means for closing the by-pass means and simultaneously expanding the sealing means upon downward movement of the conduit means, whereby fluid flow upwardly between the conduit and the well casing is prevented.

Another object is to provide a conduit means, of the type described, wherein the closure means is releasably held in inoperative position until it is desired to close the by-pass means.

A still further object is to provide a conduit means, of the type described, having a means for closing the conduit means whereby, when the by-pass means is closed and the sealing means is expanded, downward move- .aflixed externally thereon as by welding 14a.

ment of the conduit will cause an increased pressure to be exerted on the treating fluid in the well.

Yet another object is to provide a conduit means, of the type described, having a closure means closing the conduit to upward flow therethrough but opening to downward flow.

A further object is to provide a conduit means, of the type described, having a means for limiting the pressure exerted on the treating fluid by the device.

Another object is to provide a conduit means, of the type described, having a means for releasing the pressure exerted on the treating fluid in the well when said pressure attains a predetermined maximum value.

An important object is to provide a new and improved method for treating a well with fluids wherein the weight of the pipe through which the fluids are introduced into the well is employed to force the treating fluids into the earth formations.

Another object is to provide a method, of the type described, for treating a well wherein the treating fluids are subjected to a predetermined maximum pressure.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of the method of the invention and of devices constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURES 1 and 2, taken together, constitute a view, partly in section and partly in elevation, of a well casing showing a well and a device constructed in accordance with this invention in inoperative position therein, certain parts being shown schematically;

FIGURE 3 is a view, partly in section and partly in elevation, showing the device of FIGURES 1 and 2 in operative position;

FIGURES 4 and 5 constitute a view, partly in section and partly in elevation of a well casing, showing a modifled form of the device shown in FIGURES 1 through 3 in the well in inoperative position, certain parts being shown schematically;

FIGURE 4a is an enlarged fragmentary sectional view of the lateral check valve of the mandrel of FIGURE 4;

FIGURES 6 and 7, taken together, constitute a view partly in section and partly in elevation, of the modified device of FIGURES 4 and 5, showing the device in operative position; and,

FIGURES 8 and 9, taken together, constitute a view, partly in section and partly in elevation, of the modified form of the device, in position releasing the pressure on the treating fluids in the well.

Referring now to FIGURES 1 through 3 of the drawings, the assembly A includes an elongate tubular mandrel 10 which may be threaded to upper and lower sections 11 and 12, respectively, of a well pipe 13 and which is provided with a by-pass or sleeve member 14 An annular packing element or sleeve 15 constructed of a resilient material such as rubber, neoprene, or the like, is mounted on the bypass member 14 between an upper downwardly extending external annular lip 16 on the by-pass member and a lower packing retainer ring or cap 17 provided with an upwardly extending external annular lip 18. The packing element is afiixed to the lip 16 of the by-pass member 14 and to the lip 18 of the retainer ring 17 by any suitable method such as bonding or cementing. The retainer ring is slidable on the lower portion of the by-pass member and resiliently expands the packing element outwardly when said ring is moved upwardly on the by-pass member in a manner to be more fully hereinafter described. A plurality of fluid by-pass holes or grooves 26 extend longitudinally through the bypass member 14 to permit flow of fluids 3 through the bypass member between the mandrel and the packing element 15.

A closure member or plug ring 21 is slidably mounted on the mandrel below the by-pass member and is provided with a counterbore 27 in its upper end. When the closure member is moved upwardly on the mandrel, its upper end engages the lower face of the retainer ring 17 to move the ring upwardly on the by-pass member, the closure member telescoping upwardly around the lower end of the by-pass member by virtue of the counterbore 27. As the retainer ring is moved upwardly on the bypass member, the packing sleeve is resiliently compressed longitudinally and expanded radially. The upper end of the closure member thus serves as means for expanding the packing sleeve.

An O-ring seal means 28 in an annular groove 29 in the upper end of the closure member seals with the retainer ring 17 when the closure member engages said cap and an O-ring seal means 30 in an internal annular groove 31 in the bore of the closure member seals between the closure member and the mandrel 10. Thus, when the closure member is in engagement with the retainer ring, the O-ring seal means 28 and 30 seal off the by-pass holes 26 against upward flow therethrough.

The closure member is releasably held in a lower position remote from the by-pass member by means of a latching sleeve 23 slidable on the mandrel below the closure member and connected thereto by a plurality of bow springs 19 having their upper ends secured to the closure member by screws 20 and their lower ends secured to the latching sleeve by screws 22. The bow springs are bowed outwardly so that their middle portions resiliently and frictionally engage the walls of the well casing to resist longitudinal and rotational movement of the closure memher and latching sleeve relative to the casing.

A plurality of Lshaped hook members 24 extend downwardly from the latching sleeve for hooking engagement with lugs 25 projecting laterally from the mandrel (FIG- URE 2). The lugs are so positioned on the mandrel that, when the bight portions of the hook members are engaged or hooked around the lugs, the closure member is held spaced below the by-pass member and the retainer cap 17, and cannot move upwardly on the mandrel toward the bypass member. When the mandrel is moved slightly upwardly relative to the latching sleeve and rotated in a clockwise direction (when viewed from above), the lugs are moved upwardly and outwardly through the open portions of the hook members out of hooked engagement therewith, whereupon the mandrel may be moved downwardly relative to the latching sleeve (FIGURE 3).

The longitudinal movement of the mandrel in the latching sleeve and the closure member is limited by engagement of the closure member with the retainer cap and by engagement of the lugs with the latching sleeve.

When the mandrel is moved downwardly relative to the closure member, the bow springs hold the closure member stationary and the upper end of said closure member contacts the lower face of the packing retainer ring, the O-ring seal means 28 providing a fluid-tight seal there between. Further downward movement of the mandrel relative to the closure member telescopes the by-pass member into the counterbore of the closure member and the packing retainer ring is moved upwardly on the bypass member, ei'fectively decreasing the length of the packing element and increasing or expanding the outside diameter of said element to scaling contact with the wall of the casing C (FIGURE 3). A fluid-tight barrier is thus established between the casing C and the well pipe 13.

In use, the device is assembled as shown in FIGURES l and 2, the hook members 24 being engaged with the lugs 25 to hold the closure member 21 in its lower position spaced from the lower end of the by-pass member 4. The device is lowered into the well by means of the well pipe 15, as shown, the bow springs 19 frictionally engaging and sliding along the walls of the casing C. The device is lowerable through fluids within the well, such fluids flowing around the unexpanded packing element l5 and through the longitudinal fluid by-pass holes 26 through the by-pass member 14.

When the desired depth is reached, the downward movement of the device is stopped, and the desired treating fluid is introduced into the well pipe through a flow .pipe 32 connected to a well-head or fitting F at the upper end of the well pipe and to any suitable forcing means such as a pump (not shown). As the treating fluid is forced into the well, the fluid within the casing exteriorly of the pipe 13 is displaced upwardly around and through the by-pass element. The treating fluid is pumped downwardly through the lower end of the well pipe and upwardly therearound below the packing sleeve 15 until it occupies the position desired, such as opposite the perforations P in the casing C. When the casing is perforated as shown, the lower end of the well is ordinarily plugged as with cement (not shown). so that the fluid does not flow outwardly through porous formations in the lower end of the well. Obviously, if the lower end of the casing were open, the well pipe could be lowered adjacent the bottom of the well and the treating fluid displaced to the open lower end of the casing.

A valve V in the flow pipe, preferably near the well, is then closed. The mandrel is raised a short distance by means of the fitting F, the bow springs holding the latching sleeve stationary in the casing, until the lugs 25 are positioned opposite the open portions of the hook members. The mandrel is then rotated in a clockwise direction (as viewed from above) to move the lugs through the open portions of the hook members and out of engagement with their bight portions, the bow springs holding the latching sleeve against rotation. The mandrel is then lowered, the latching sleeve and the closure member being frictionally held against movement in the casing by the bow springs, until the various parts assume the positions in FIGURE 3.

The well pipe is then further lowered in the casing, the closure member, by-pass member and the packing element closing the annular space between the well pipe and the casing, and the valve V closing the flow path through the well pipe. The assembly is lowered further downwardly in the well casing, whereupon the weight of the well pipe causes an increased pressure to be exerted on the fluid below the packing element, thereby forcing the treating fluid outwardly through the perforations P to perform the desired treating operation on the well formations, the fluid being prevented from flowing outwardly through the lower end of the casing by virtue of the usual cement plug (not shown) in the lower end of the well. Obviously if the casing is imperforate and the lower end of the well is open, the treating fluid is forced outwardly through the lower end of the casing into the earth formations therebelow.

If it is desired to force additional treating fluids through the perforations, the well pipe is again lifted, the bow springs holding the closure member so that the openings 26 through the by-pass member are again opened, and the packing element is retracted to allow additional fluid to flow downwardly below the packing element. Obviously, if this method is used, sufficient treating fluid is initially introduced into the well so that, as the well pipe is subsequently raised and lowered, sufficient treating fluid will be available to be forced through the perforations. Any number of additional strokes may be made with the well pipe, the by-pass being opened on upward movement of the well pipe and closed on downward movement thereof. Alternatively, additional treating fluid can be introduced through the well pipe by opening the valve V and pumping the fluid downwardly through the well pipe. In either case, after additional fluid has been moved below the assembly, the well pipe is again lowered, the valve V being closed, whereupon the closure member and the packing element close off the annular space between the well pipe and the well casing in the manner previously described to force the fluid through the perforations.

Obviously, th high pressures developed below the packing element are confined to the space therebelow and are not imposed on the casing above the packing element. When the well pipe is lifted in preparation for another downward stroke and the by-pass is opened, the pressure imposed below the packing element is released and is dissipated in the casing thereabove.

While the well pipe has been described as being lowered in the casing, greater pressure can be developed by dropping or snubbing the well pipe through the desired distance.

It will be seen that a new and improved conduit means has been shown and described for introducing a fluid into a well casing at a predetermined location in the well. It will also be seen that the conduit means is provided with a by-pass means and an expansible sealing means for sealing between the conduit means and the well casing whereby, when the by-pass means is closed and the sealing means is expanded, the annular space between the casing and the conduit means is closed to prevent upward flow of fluids therethrough. It will further be seen that a closure means for closing the by-pass means and expanding the sealing means has been shown and described, the closure means being releasably held in inoperative position until it is desired to close the annular space between the conduit means and the well casing.

It will particularly be seen that a method for inroducing fluids into a well casing and forcing said fluids into the earth formations has been shown and described which includes lowering a pipe into a well, introducing a fluid through the pipe into the well, sealing between the pipe and the well casing at a level above the point at which it is desired to force the fluid into the earth formations, and lowering the pipe to force the fluid into the earth formations; and that a means for performing such operation has been likewise shown and described.

It will be seen that, with the method and means described, high pressures may be exerted by means of the Weight of the well pipe on the fluids to inject them into the earth formations. It will particularly be seen that the high pressures are exerted only on the well casing below the sealing means whereby the possibility of rupturing the casing above the sealing means is obviated; also, that the method and apparatus shown and described eliminate the need for high pressure pumping equipment at the surface, as the only pumping equipment required is that needed to circulate the treating fluid into position in the well.

It is especially apparent that as much treating fluid as is desired may be introduced into the earth formation by the operation of the device several times or through a greater or lesser distance.

A modified form of apparatus for carrying out the invention is shown in FIGURES 4 through 9, wherein a means is provided to retain the pressure developed by the device during an injection stroke so that, as the device is raised for another injection stroke, the pressure imposed on the earth formation is not released. This modified form of the invention further provides a means for releasing the pressure imposed by the device when a predetermined maximum pressure is attained.

This modified assembly B includes an inner elongate tubular mandrel or plunger 50 threaded at its upper end to an upper section 11 of the well pipe and provided with an external annular flange 51 at its lower end. The mandrel is telescoped into the upper end of an elongate tubular sleeve 52 and is retained therein by the engagement of an internal annular flange 53 near the upper end of the sleeve with the flange 51 on the mandrel. A packing means 54, shown to be of the V or chevron type, seals between the mandrel and the sleeve 52 and is retained in position in the sleeve by a gland ring 55 threaded into the upper end of the sleeve.

A check valve assembly 56 is provided in the lower end of the mandrel to permit downward flow through the mandrel but to prevent upward flow therethrough. The check valve assembly includes a ball 57 engageable with a downwardly facing annular seat 58 in the lower end of the bore 59 of the mandrel, and a check valve housing 60 enclosing the ball and threaded into the lower end of the mandrel. The housing has flow ports 61 through its walls whereby, when the ball is moved away from the seat, fluids, may flow downwardly through the mandrel bore and outwardly through the flow ports. A spring 63 in the housing biases the ball upwardly into engagement with the seat 58.

The mandrel or plunger 50 is slidable downwardly in the sleeve from the upper position determined by the engagement of the flanges 51 and 53 and is releasably retained in the upper position by a shearable pin 64 extending through the flange 53 in the upper end of the sleeve into a corresponding hole in the mandrel.

A tubular body, outer mandrel or housing 65 is slidably mounted on the lower part of the sleeve 52, and a tubular lower housing sub 67 is threaded to the lower end of the housing and is provided with a counterbore 68 in its upper end. A split ring 66 is positioned in an external annular groove near the lower end of the sleeve slidable in the internal annular recess or counterbore 68 to limit movement of the sleeve upwardly in the housing. The counterbore or recess 68 is of such length that the ring 66 is slidable a limited distance longitudinally therein, to permit a limited longitudinal movement of the sleeve 52 relative to the housing 65, for a purpose to be hereinafter more fully explained. An upwardly facing shoulder 69 at the lower end of the counterbore provides a stop shoulder engageable with the split ring 66 to limit downward movement of the sleeve in the housing sub. A frangible pin 70 inserted through the housing into the sleeve releasably retains the sleeve in its lower position in the housing.

An annular by-pass or sleeve member 71 is aflixed to the housing 65, as by welding, and is provided with a plurality of longitudinal fluid by-pass passages or holes 72 therethrough. A resilient packing sleeve or element 73, of a material such as rubber, neoprene, or the like, is aflixed to the outer surface of the by-pass member by means such as bonding, cementing, or the like, and is re tained thereon by an external downwardly extending annular lip 76.

A plurality of outwardly extending gripping members '74 are afl'ixed -o-r imbedded in the packing sleeve and are provided with gripping teeth adapted to engage the casing wall on lateral outward movement to prevent upward movement of the packing element and the housing 65 to which the packing element is secured. The gripping membe-rs rare movable laterally outwardly on expansion of the resilient packing sleeve, so that the portion of the sleeve carrying the gripping members serves as expander means for expanding the gripping members to gripping position.

A downwardly and outwardly extending annular pressure-retaining lip 75 on the lower outer surface of the packing sleeve or element is normally engageable with the casing wall, and when fluid pressure is applied to the under side of the packing sleeve the lip seals with the wall to prevent fluid flow therebetween, and the applied pressure expands the entire packing sleeve to force the gripping teeth into gripping engagement with the casing. The lip 75 is normally in light rubbing contact with the casing wall to seal therewith, the contact being sufficiently light to avoid undue wear on the lip as it is lowered into the well.

A closure member is slidable on the housing below the bypass member between an upper position engaging the lower end of the bypass member and a lower position spaced therefrom. An O-ring seal means 86 in an annular groove in the upper end of the closure member seals between the closure member and the by-pass member outwardly from the by-pass passage holes 72, and an O-ring seal means 84 in an internal annular groove 85 in the bore of the closure member seals with the outer surface of the housing.

Thus, when the closure member is in sealing contact with the by-pass member, the by-pass passages are closed off, particularly to flow upwardly therethrough from below.

A latching sleeve 23, similar to the latching sleeve in the form already described, is mounted on the housing below the closure member and is connected to the closure member by means of the arcuate bow springs 19. The central portions of the bow spring-s engage the bore Wall of the well casing to frictionally resist movement of the closure member in the casing. A plurality of J-shaped hooks 24 extend downwardly from the latching sleeve and releasably engage the lugs 25' to hold the closure member in its lower position spaced from the lower end of the by-pass member, as has already been described.

The hooks 24 and the lugs 25 thus function to releasably hold the closure member spaced below the lower end of the by-pass member, and when disengaged permit the housing to be lowered until the by-pass member ongages the closure member.

A lateral port $53 is formed in the wall of the housing above the by-pass member, and a similar port 89 is formed in the wall of the housing below the by-pass member, and these ports 88 and 89 are adapted to cooperate with corresponding ports 9t) and 91 through the wall of the sleeve 52, so that, when the port-s $8 and 90 are aligned and the ports 89 and 91 are similarly aligned, fluids may flow inwardly from the exterior of the housing below the by-pass member to the interior of the sleeve and thence upwardly through the sleeve and outwardly through the ports 88 and 90.

As shown in FIGURE 5, the several ports are so positioned that when the sleeve is in its lower position in the housing, the ports 88 and 89 are out of communication with the ports 9@ and 91, respectively, but are aligned for communication when the sleeve is moved to its upper position shown in FIGURES 8 and 9. O-ring seal means 92 and 93 are mounted in grooves in the sleeve 52 on either side of the port 9%, and the O-ring seal means 96 and 97 are mounted in grooves in the sleeve on either side of the port 91, to prevent flow therethrough when the sleeve is in the lower position in the housing. Thus, when the sleeve 52 is in its lower position in the housing, the ports and 91 are closed o'lf, but when the sleeve is in its upper position, the ports are opened so that the fluid pressures below the 'by-pass member may equalize with those above.

A tubular closing sub 1% is threaded to the lower end of the lower housing sub 67 and is provided with a check valve 194 opening to downward flow but closing to upward flow therethrough. The valve includes a valve plug or ball 105 retained in the bore of the closing sub below an annular valve seat 192 by a tubular valve body 108, the ball being biased upwardly toward seating engagement with the seat 1492. by means of a spring 1%.

A check valve 14 is provided in the wall of the plunger or mandrel 56 near the upper end thereof. The valve is mounted in a radial port lit) opening through the wall of said mandrel and having a counterbore 1-14 in its outer portion. The check valve includes a ball 111 urged outwardly by a spring 115 against an annular seat 112 in a seat member 1*13 threaded into the oounterbore 114. The spring 115 acts against the bottom of said counterbore. This check valve thus is closed by pressure within the mandrel but is openable to pressure outside said mandrel in excess of that within to permit fluid flow thereinto. The check valve N9 is located in the plunger or mandrel 50 at an elevation such that said check valve remains above the upper end of the sleeve 52 even when the mandrel is moved to its lowermost position insaid sleeve.

In use, the assembly B is connected to the pipe 11 as shown in FIGURES 4 and 5, the shearable pins or screws 64 and being installed to releasably hold the sleeve in its lower position in the housing and the mandrel 50 in its upper position in said sleeve. The closure member 8t) is retained in its lower position on the housing 65 by engagement of the lugs 25 in the hook members 24 so that the by-pass holes 72 through the bypass member 71 remain open.

The mandrel or plunger 50 is threaded to an upper section 11 of a well pipe 13 as shown and the assembly B is lowered in the well by means of said well pipe, the lip of the packing element 73 making light rubbing contact with the wall of the casing C. The assembly is lowerable through fluids in the well inasmuch as the by-pass holes are open, permitting fluid flow therethr-ough. When the desired level is reached, the descent of the pipe 13 is stopped and the flow pipe 32 with a valve V is connected thereto by means of the fitting F.

The desired treating fluid is then pumped downwardly through the lower end of the well pipe and upwardly until it is positioned adjacent and above the perforations P. As has already been described, the lower end of the well is plugged in the event it is desired to force the fluid through perforations; or the fluid may be forced outwardly through formations exposed in the open lower end of the well bore. The valve V is then closed to prevent further addition of fluid, and the well pipe is slowly raised and then rotated in a clockwise direction (when viewed from above) to release the lugs 25 from the hooks 24 and is then lowered until the by-pass member engages the closure member.

The closure member closes ofl the by-pass holes 72 by the sealing engagement of the O-ring seal means 86 with the by-pass member, and the lip 75 of the packing element '73 engages the wall of the casing to complete the closure between the well pipe and the casing. With the check valve 56 closed to upward flow therethrough, the well casing is thus completely closed against upward flow.

Downward movement of the well pipe then increases the pressure below the packing element 73 by virtue of the compression of any fluids therebelow. This increase in pressure, acting on the lower face of the packing element, expands the element to move the gripping members 74 outwardly until the teeth 7? grip the wall of the casing to hold the housing against movement in the easmg.

Continued downward movement of the well pipe and the plunger or mandrel 5d shear the pin 64, permitting downward movement of the mandrel in the sleeve 52 and the housing. Upward movement of the packing element and the sleeve is prevented by the gripping engagement of the gripping teeth 77 with the casing Wall.

Continued downward movement of the mandrel dis places the fluid within the sleeve and housing downwardly through the check valve 104 in the lower closing sub 10%, the pressure beneath the packing element being further increased. When the downward stroke, limited by engagement of the check valve housing 6% with an internal annular flange 117 in the lower housing sub, 'is completed, the mandrel is then elevated, the check valve 104 closing and the check valve 56 opening to admit more fluid from the pipe 13. The closure member 86 remains in sealing contact with the by-pass member because of the continued upward force exerted thereon by the increased pressure below the packing element.

Additional fluid from the well pipe 13 is admitted through the valve V and check valve 56 into the bore of the sleeve and the housing, while the fluid displaced below the packing element is confined therebelow by means of the check valve 104. Additional downward strokes of the mandrel displace additional fluid from the lower end of the assembly, thereby increasing the pres- I sure and forcing the treating fluid outwardly through the perforations P, or through the open end of the casing into the formations exposed in the open lower end of the Well bore.

As the fluid within the mandrel is displaced from the lower end of the device, additional fluid is introduced through the valve V. Also, some fluid from the annular space around the well pipe above the packing element will flow inwardly through the check valve 109 to the interior of the mandrel if the fluid level in the well pipe drops below that in the casing.

The sleeve 52 is subjected to an upward force as the pressure is increased below the packing element. When the mandrel or plunger is near the lower portion of its stroke, such that the pressure within the sleeve is essentially the same as that developed below the packing element, the upward force is equal to the product of the upward pressure differential acting against the annular area between the inner surface of the housing 65 and the outer surface of the plunger or mandrel 58. When this force exceeds a predetermined amount, the pin 70 is sheared and the sleeve moves upwardly in the housing to align the ports 88 and 89 with the ports 90 and 91, respectively. The fluid pressure below the device is thus released or equalized with that in the annular space above.

With the pressures equalized across the packing element, the gripping members 74 no longer grip the casing, and the entire device may be removed from the well.

If it is desired to remove the device from the casing before the pin 7% has been fractured, the plunger or mandrel Si) is moved upwardly until the flange 51 engages the flange 53, whereupon the sleeve 52 is moved upwardly. The housing being retained in position by means of the gripping members 74, the pin 70 is mechanically sheared or fractured to allow release of the pressure below the packing element.

Obviously this modified form of the invention has all the advantages of the form first described, but in addition, the pressure built up by the device may be limited to any value desired. It will also be seen that when the pressure is built up to the desired value, the pressure is released from beneath the device. It will be seen that the pressure developed by the device is retained beneath the packing element thereof as additional strokes are made by the plunger or mandrel h.

The foregoing description of the invention is explanatory only, and changes in the details of the method and constructions illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. The method of treating and completing cased wells comprising the sequential steps of: introducing a well pipe into a well; introducing a treating fluid through the well pipe into the casing of said well and placing said fluid adjacent an opening in said casing; closing the space between said casing and said well pipe by a closure; closing the well pipe; subjecting the treating fluid to pressures developed by downward movement of said well pipe and the closure between the casing and the well pipe to force said fluid outwardly through said opening into the stratum surrounding said well; introducing additional treating fluid through said closure between the casing and said well pipe; and subjecting such additional treating fluid to pressure developed by downward movement of said well pipe and of said closure between said casing and said well pipe to force such additional treating fluid outwardly through said openings into the stratum surrounding said well.

2. The method of treating and completing cased wells including the sequential steps of: introducing a well pipe into a well casing; introducing a treating fluid into the casing of said well and placing said fluid adjacent an opening in said casing; closing by a packing means the space between said casing and said well pipe at a point spaced above the opening in the casing; closing the well pipe to upward flow therethrough; lowering the well pipe and the packing means toward said opening in the easing to increase the pressure on said fluid and force said fluid outwardly through said opening in the casing; opening the space closed by the packing means between the casing and the well pipe; introducing additional treating fluid through the well pipe into the well casing below said packing means; reclosing said space between said casing and said well pipe; and again lowering the pipe and the packing means toward the opening in the casing to again increase the pressure on such treating fluid and force said fluid outwardly through said opening in the casing.

3. The method of treating and completing cased wells including the sequential steps of: introducing a well pipe into a well casing, said well pipe being provided with a packing means thereon; introducing a treating fluid through said well pipe into the casing of said well and placing said fluid adjacent an opening in said casing; utilizing said packing means to close the space between said tubing and said casing above said opening in said casing; closing said well pipe to flow from below; lowering said well pipe and simultaneously lowering said packing means in said casing toward the opening in said casing to increase the pressure on said fluid by virtue of the weight of said pipe to force said fluid outwardly through said opening in said casing; opening the space between said tubing and said casing to admit additional treating fluid therepast to the space below said packing means; reclosing the space between the tubing and said casing; and again lowering said well pipe and simultaneously lowering said packing means in said casing toward said opening in said casing to force additional treating fluid outwardly through said opening in said casing.

4. A well tool for use in a cased well, said tool including: a tubular body; a packing means on said body sealingly engageable with the casing of said Well to seal between the casing and the body, said packing means having a by-pass means therethrough; closure means movable on said body between a position spaced from said bypass means and a position closing said by-pass means; and a plunger in said body movable longitudinally downwardly in said body a substantial distance and means on said plunger and body initially releasably holding said plunger against such downward movement therein.

5. A well tool for use in a cased well, said tool including: a tubular body having an expansible packing means thereon sealingly engaging the casing of said well when said packing means is expanded; a packing expander means movable on said body between a first position remote from said packing means and a second position engaging and expanding said packing means; said packing means having a longitudinal passage therethrough; said expander means closing said passage when in said packing expanding position; and a plunger in said body slidable longitudinally therein.

6. A well tool for use is a cased well, said tool including: a tubular body having an expansible packing means thereon sealingly engaging the casing of said well when said packing means is expanded; a packing expander means movable on said body between a first position remote from said packing means and a second position engaging and expanding said packing means; said packing means having a longitudinal passage therethrough; said expander means closing said passage when in said second position; holding means on said body releasably holding said expander means in said first position; and a plunger slidable longitudinally in said body.

7. A well tool for use in a cased well, said tool including: a tubular body having an expansible packing means thereon sealingly engaging the casing of said well when said packing means is expanded; a packing expander means movable on said body between a first position remote from said packing means and a second position engaging and expanding said packing means; said packing means having a longitudinal passage therethrough; said expander means closing said passage when said expander means is in said second position; means on said expander means engaging the wall of said casing to restrain said expander means against movement therethrough; holding means on said body and on said expander means cooperating to releasably hold said expander means in said first position; said holding means being releasable on upward movement of said body in said well to permit said body to move relative to said expander means until said expander means is in said second position; and plunger means slidable in said tubular body and having sealing engagement therewith.

8. A well tool for use in a well, said tool including: a tubular sleeve; a body slidably mounted in said sleeve for longitudinal movement therein; an expansible packing means on said body above said sleeve sealingly engaging the bore wall of a well when said packing means is expanded therein; said sleeve engaging and expanding said packing means when said body is moved downwardly in said sleeve to a lower position therein; said packing means having a passage therethrough; said sleeve closing said passage when said body is in said lower position; means on said sleeve and said body limiting upward movement of said body to an upper position in said sleeve; said sleeve being spaced from said packing means when said body is in said upper position in said sleeve and means on such sleeve engageable with the bore wall of said well for resisting movement of said sleeve therein.

9. A well tool for use in a well, said tool including: a tubular sleeve; a body slidably mounted in said sleeve for longitudinal movement therein; an expansible packing means disposed on said body above said sleeve sealingly engaging the bore wall of a well when said packing means is expanded therein; said sleeve engaging and expanding said packing means when said body is moved downwardly in said sleeve to a lower position therein; said packing means having a passage therethrough; said sleeve closing said passage when said body is in said lower position; means on said sleeve and said body limiting upward movement of said body to an upper position in said sleeve; said sleeve being spaced from said packing means when said body is in said upper position in said sleeve; resisting means on said sleeve engaging the bore wall of said Well and resisting movement of said sleeve therein; and releasable means on said sleeve and said body releasably holding said body in said upper position in said sleeve.

16. A well tool to be incorporated in a string of pipe in a well, said tool including: a tubular sleeve; a body slid ably mounted in said sleeve for longitudinal movement therein; an expansible packing means disposed on said body above said sleeve, said packing means sealingly engaging the bore wall of a well when said packing means is expanded therein; said sleeve engaging said packing means toexpand said packing means when said body is moved downwardly in said sleeve to a lower position therein; said packing means having a passage therethrough; said sleeve closing said passage when said body is in said lower position; means on said sleeve and said body limiting upward movement of said body to an upper position in said sleeve; said sleeve being spaced from said packing means when said body is in said upper position in said sleeve; resilient means on said sleeve; resisting means on said resilient means, said resilient means biasing said resisting means into frictional engagement with the bore wall of said well to resist movement of said sleeve therein; releasable hook means on said sleeve and said body releasably holding said body in said upper position in said sleeve, said hook means being releasable to permit longitudinal movement of said body to said lower position in said sleeve when said body is moved upwardly and is rotated in said well; and means for closing said string of pipe.

11. A well tool for use in a well, said tool including: a tubular housing; a tubular body mounted in said housing for limited longitudinal movement between a lower and an upper position therein; holding means holding said body in said lower position in said housing; a packing means on said housing having a passage therethrough and engageable with the bore wall of said well to seal therewith against upward flow between said packing means and the bore wall of said well; expansible gripping means on said housing engageable with the bore wall of said well to prevent upward movement of said housing therein when said gripping means is expanded; a control sleeve slidably mounted on said housing below the packing means and engaging said packing means and closing the passage when said housing is moved downwardly to a lower position in said sleeve, said control sleeve opening said passage when said housing is above said lower position; securing means on said housing and said control sleeve releasably holding said housing in an upper position in said sleeve; resisting means on said control sleeve engageable with the bore wall of said well to resist movement of said sleeve therein; a central tubular member slidable longitudinally in said body between an upper and a lower position therein; sealing means on said central member and said body sealing therebetween; means releasably holding said central member in said upper position in said body; valve means in said central member permitting downward flow therethrough but preventing reverse flow therethrough; and means on said gripping means moving said gripping means to expanded position when the pressure below said gripping means is increased.

12. A well tool for use in a well, said tool including: a tubular housing; a packing means on said housing having a passage therethrough and engaging the bore wall of said well to prevent upward flow between said packing means and said bore wall; a control sleeve slidably mounted on said housing below said packing means to close said passage when said housing is moved downwardly in said sleeve to a lower position therein; said control sleeve opening said passage when said housing is in said upper position in said sleeve; securing means on said housing and said control sleeve releasably securing said housing in said upper position in said sleeve, said securing means releasing said housing for movement to said lower position in said sleeve on upward and rotative movement of said housing in said sleeve; a central tubular member having a longitudinal bore therethrough slidable longitudinally in said housing between an upper and a lower position therein and extending upwardly from said housing; sealing means on said central member and said housing sealing therebetween; a first valve means on said central member closing the bore thereof to upward flow but opening to downward flow therethrough; said hou ing having a port opening to the exterior thereof below said packing means and said by-pass means; a second valve means on said housing opening said port to outward flow therethrough but closing to inward flow therethrough; expansible gripping means on said housing engageable with the bore wall of said well to prevent upward movement of said housing when said gripping means is expanded; and means on said gripping means expanding said gripping means on increase of pressure below said packing means.

13. A well tool for use in a well, said tool including: a tubular housing; a packing means on said housing having a passage therethrough and engaging with a bore wall of said well to prevent upward flow between said packing means and said bore wall; a control sleeve slidably mounted on said housing below said packing means to close said passage when said housing is moved downwardly to a lower position in said sleeve; said control sleeve opening said passage when said housing is in an upper position in said sleeve; securing means on said housing and said control sleeve releasably securing said housing in said upper position in said sleeve, said securing means releasing said housing for movement to said lower position in said sleeve on upward and rotative movement of said housing in said sleeve; a central tubular member having a longitudinal bore therethrough slidable longitudinally in said housing between an upper and a lower position therein and extending upwardly from said housing; sealing means on said central member and said housing sealing therebetween; a first valve means on said central member closing the bore through said member to upward flow but opening to downward flow therethrough; said housing having a port opening to the exterior thereof below said packing means and said passage; a second valve means on said housing opening said port to outward flow therethrough but closing to inward flow therethrough; expansible gripping means on said housing engageable with the bore wall of said well to prevent upward movement of said housing when said gripping means is expanded; means on said gripping means expanding said gripping means on increase of pressure below said packing means; said housing having a bypass means providing fluid communication around said packing means; and releasable means on said by-pass means controlling flow through said by-pass means; said releasable means opening said by-pass means only on the imposition of a certain predetermined upward pressure differential across said packing means.

14. A well tool for use in a well, said tool including: a tubular housing having a packing means thereon engaging with the bore wall of said well to prevent upward flow between said packing means and said bore wall; said packing means having a passage therethrough; a control sleeve slidably mounted on said housing below said packing means to close said passage when said housing is moved downwardly in said sleeve to a lower position therein; said control sleeve opening said passage when said housing is in an upper position in said sleeve; securing means on said housing and said control sleeve releasably securing said housing in said upper position in said sleeve, said securing means releasing said housing for movement to said lower position in said sleeve on upward and rotative movement of said housing in said sleeve; a central tubular member having a longitudinal bore therethrough slidable longitudinally in said housing between an upper and a lower position therein and extending upwardly from said housing; sealing means on said central member and said housing sealing therebetween; a first valve means on said central member closing the bore therethrough to upward flow but opening to downward flow therethrough; said housing having a port opening to the exterior thereof below said packing means and said by-pass means; a second valve means on said housing opening said port to outward flow therethrough but closing to inward flow therethrough; expansible gripping means on said housing engageable with the bore wall of said well to prevent upward movement of said housing when said gripping means is expanded; means on said gripping means expanding said gripping means on increase of pressure below said packing means; a by-pass means in said housing providing fluid communication around said pack-ing means; releasable means on said by-pass means controlling flow through said by-pass means; said releasable means opening said by-pass means only on the imposition of a predetermined upward pressure differential across said packing means; and holding means on said central member and said housing releasably holding said central member in said upper position in said housing; said holding means being releasable on the application of a predetermined downward force on said central member.

15. A well tool of the character set forth in claim 14 wherein the holding means comprises a shearable member.

16. A well tool including: a tubular body having sealing means thereon engageable with the bore wall of a well to seal between said body and the bore wall; means providing a flow course past said sealing means; closure means slidable on said body between a position spaced from said flow course past said sealing means and a position on said body closing said flow course; plunger means slidable longitudinally downwardly a substantial distance in said body for forcing fluids downwardly through said body to increase the pressure below said body; means releasably connecting said plunger means to said body for releasably holding said plunger means against such downward movement relative to said body; and sealing means carried by said body and engaging said plunger means to seal therebetween.

17. A well tool for use in a cased well, said tool including: a tubular body; a packing means on said body sealingly engageable with the casing of said well to seal between the casing and the body, said packing means having a plurality of longitudinal passages therethrough adjacent the exterior surface of the body; a closing sleeve slidably disposed on said body below said packing means, said sleeve being slidable longitudinally upwardly on said body to a position engaging said packing means to close the passages on upward movement of said sleeve on said body; a plunger member slidable longitudinally in said body from an upper position to a lower position for forcing fluids downwardly through said body to increase fluid pressure below said body; and means releasably securing said plunger means to said body to prevent such down ward movement of said plunger relative to said body and releasable on the application of a downward force to said plunger means to permit said plunger means to move downwardly of said body.

18. A well tool for use in a cased well, said tool including: a tubular body; a packing means on said body sealingly engageable with the casing of said well to seal between the casing and the body, said packing means having a bypass means therethrough exteriorly of said body; closure means freely and non-rotatably longitudinally movable on said body between a position spaced from said bypass means and a position closing said bypass means; releasable holding means on said tubular body and said closure means initially releasably holding said closure means spaced from said bypass means; and means opera tively associated with said closure means and engageable with the casing of said well to cause relative non-rotatable longitudinal movement of said closure means relative to said bypass means upon non-rotative downward movement of said tubular body in the well after said releasable initial holding means has released said closure means for non-rotatable longitudinal movement relative to said tubular body.

19. The method of treating and completing cased wells comprising the sequential steps of: introducing a well pipe into a well in spaced relation to the casing of the well; introducing a treating fluid through the well pipe into the casing of said well and placing said fluid adjacent an opening in said casing; closing the space between said casing and said well pipe above said opening; closing the well pipe; and subjecting the treating fluid to pressures developed by downward movement of said well pipe and simultaneous downward movement of said closure between the casing and said well pipe to force said fluid outwardly through said opening into the stratum surrounding said well.

20. The method of treating and completing cased wells comprising the sequential steps of: introducing a well pipe into a well casing in spaced relation thereto; introducing a treating fluid into the casing of said well and placing said fluid adjacent an opening in said casing; closing by a packing means the space between said casing and said well above the opening in the casing; closing the well pipe to upward flow therethrough; and lowering the well pipe and the packing means toward the opening in the casing to increase the pressure on said fluid and force the fluid outwardly through said opening in the casing.

21. In apparatus adapted to be lowered in a well casing disposed in a well bore: a mandrel; a packing structure on said mandrel including a sleeve mounted externally on said mandrel, and an elongate tubular normally retracted pliant, elastic packing means mounted externally on and in closely surrounding engagement with the exterior of said sleeve throughout its length, said packing means being compressible longitudinally to be expanded on said sleeve to sealingly engage the well casing, said sleeve supporting said packing means thereon throughout the length of the bore of said packing means; means for expanding said packing means against the well casing; means providing a plurality of longitudinally extending fluid bypass passages through said packing structure extending externally of said mandrel and internally of said packing means and opening to the exterior of said mandrel longitudinally beyond opposite ends of said packing means; closure means for selectively opening and closing said bypass passages; and releasable holding means on said mandrel and closure means below said packing structure engageable for initially holding said closure means in position wherein said bypass is open while said apparatus is being lowered in the well casing and releasable to permit said closure means to move to bypass closing position, said bypass closure means being mov able to position closing said bypass passages upon longitudinal downward movement of said mandrel.

22. In apparatus to be lowered in a well casing disposed in a well bore: a mandrel; a sleeve mounted externally on said mandrel; normally retracted hydraulically expansible casing gripping means on said sleeve for anchoring said sleeve in the well casing; tubular normally retracted pliant, elastic packing means mounted externally on said sleeve and in surrounding supporting engagement with the exterior of said sleeve below said gripping means and adapted to be expanded on said sleeve to sealingly close 01f flow between'said sleeve and'the well casing; means providing longitudinally extending fluid bypass pas sage means extending externally of said mandrel and internally of said packing means and gripping means and opening to the exterior of said mandrel longitudinally beyond opposite ends of said gripping means and said packing means, said bypass passage means enabling fluid from below said packing means and said gripping means to pass thereabove to prevent movement of said gripping lid means upon downward movement of said mandrel in said casing after said holding means is released; said hydraulically operable gripping means being actuatable by fluid pressure in said casing below said packing means for expansion into anchoring engagement with the well casing when said bypass passage means is closed.

23. In apparatus to be lower-ed in a well casing disposed in a well bore: a mandrel; a'sleeve mounted externally on said mandrel; normally retracted hydraulically expansible casing gripping means on said sleeve for anchoring said sleeve in the well casing; means for expanding said gripping means into anchoring engagement with the Well casing; tubular normally retracted pliant, elastic packing means mounted externally on said sleeve and in surrounding supporting engagement with the exterior of said sleeve below said gripping means and adapted to be expanded on said sleeve to sealingly close oil flow between said sleeve and the well casing; means providing a plurality of longitudinally extending fluid bypass passages extending externally of said mandrel and internally of said packing means and said gripping means and opening to the exterior of said mandrel longitudinally beyond opposite ends of said packing means and said gripping means, said passages enabling fluid from below said packing means and said gripping means to pass thereabove to prevent movement of said gripping means to anchoring position; closure means for selectively opening and closing said bypass passages; releasable holding means holding said bypass closure means in open condition while the apparatus is being lowered in the well casing and releasable to permit said closure means to move to closed condition, said closure means being movable to position closing said bypass passages upon downward movement of said mandrel in said casing after said holding means is released; and means operatively associated with said closure means and engageable with the well casing to cause movement of said closure means from open condition to closed condition upon such downward movement of said mandrel in the well casing after said releasable holding means has been released.

References Cited by the Examiner UNITED STATES PATENTS 845,677 2/07 Bare 166l88 X 2,282,987 5/42 Bennett l66-183 2,355,259 8/44 Bancroft et a1. l66l77 X 2,675,880 4/54 Baker 166l83 X 2,691,418 10/54 Connolly 166-129 3,068,523 11/61 Clark et al l66l29 CHARLES E. OCONNELL, Prmary Examiner.

BENJAMIN BENDETT, Examiner. 

1. THE METHOD OF TREATING AND COMPLETING CASED WALLS COMPRISING THE SEQUENTIAL STEPS OF: INTRODUCING A WELL PIPE INTO A WELL; INTRODUCING A TREATING FLUID THROUGH THE WELL PIPE INTO THE CASING OF SAID WELL AND PLACING SAID FLUID ADJACENT AN OPENING IN SAID CASING; CLOSING THE SPACE BETWEEN SAID CASING AND SAID WELL PIPE BY A CLOSURE; CLOSING THE WELL PIPE; SUBJECTING THE TREATING FLUID TO PRESSURES DEVELOPED BY DOWNWARD MOVEMENT OF SAID WELL PIPE AND THE CLOSURE BETWEEN THE CASING AND THE WELL PIPE TO FORCE SAID FLUID OUTWARDLY THROUGH SAID OPENING INTO THE STRATUM SURROUNDING SAID WELL; INTRODUCING ADDITIONAL TREATING FLUID THROUGH SAID CLOSURE BETWEEN THE CASING AND SAID WELL PIPE; AND SUBJECTING SUCH ADDITIONAL TREATING FLUID TO PRESSURE DEVELOPED BY DOWNWARD MOVEMENT OF SAID WELL PIPE AND OF SAID CLOSURE BETWEEN SAID CASING AND SAID WELL PIPE TO FORCE SUCH ADDITIONAL TREATING FLUID OUTWARDLY THROUGH SAID OPENINGS INTO THE STRATUM SURROUNDING SAID WELL. 